Apparatus for folding of envelope blanks

ABSTRACT

A plurality of folding stations are provided, corresponding in number to the plurality of folding operations to be carried out on a blank and including an initial station and a terminal station. Rotary folding grippers and folding blades are provided on the respective folding stations and drive means serves for rotating the grippers and blades of the initial folding station so as to effect folding of a blank in one direction, and the grippers and blades of all other folding stations so as to effect folding of the blank in an opposite direction. Removing devices remove folded blanks from the terminal folding station.

United States Patent Honsel 51 Feb. 26, 1974 APPARATUS FOR FOLDING OF ENVELOPE BLANKS [76] Inventor: Karl-Heinz Honsel, l-leidelberger [30] Foreign Application Priority Data FOREIGN PATENTS OR APPLICATIONS Germany France 93/61 Primary ExaminerTravis S. McGehee Assistant Examiner-Leon Gilden Attorney, Agent, or Firm-Michael S. Striker [57] ABSTRACT A plurality of folding stations are provided, corresponding in number to the plurality of folding operations to be carried out on a blank and including an initial station and a terminal station. Rotary folding grippers and folding blades are provided on the respective folding stations and drive means serves for rotating the grippers and blades of the initial folding station so as to effect folding of a blank in one direction, and the grippers and blades of all other folding stations so as to effect folding of the blank in an opposite direction. Removing devices remove folded blanks from the terminal folding station.

13 Claims, 5 Drawing Figures PAIENTEDFEBZBIQH 3.793.926

SHEET 2 [1F 3 PATENTED FEBZS 1974 saw 3 11$ 3 APPARATUS FOR FOLDING OF ENVELOPE BLANKS BACKGROUND OF THE INVENTION The present invention relates generally to an apparatus for folding of envelope blanks, and more particularly to an apparatus for folding envelope blanks requiring a plurality of folding operations.

It is already known to provide envelope blanks which in the unfolded (that is in the planar) state have two flaps which must be folded over and which are provided on certain marginal portions with adhesive, frequently with self-adhesive strips or the like. Folding blanks of this type can be readily folded and sealed, that is without requiring moistening, but only if the surfaces to be contacted and sealed with one another are both coated with the self-adhesive material. For this reason such folding envelopes have a second closure flap which is located beneath the actual outer closure flap so that the surface portions which are provided with the self-adhesive material will not come in contact with one another while the envelope is being stored, that is prior to the time of use.

For storing purposes it is necessary to protect the self-adhesive material against light because light tends to disadvantageously effect, if not destroy, the adhesive capability of this material. For this reason the blanks must be so folded in making of the envelope that the actual upper closure flap is in a position which it will later seal when the envelope is to be sealed, whereas the lower closure flap must be so folded that its surface provided with the self-adhesive material faces the surface of the envelope.

It is known to fold such blanks on apparatus which first provides a preliminary bending of the blank material along the fold lines, whereupon the blank is supplied to a further station of the apparatus using essentially two cooperating rollers and a deflecting device for the leading portion of the blank which is to be folded over. The problem with this prior-art approach resides in the fact that the blank to be folded must be advanced with a sliding movement until it is engaged at the leading edge of the portion to be folded, by the rollers, because the leading portion of the blank must be folded back and must therefore remain freely movable. It has however been observed that in such operations the development of a fold or crinkle frequently occurs, and this of course leads to a significant amount of wastage in the production of envelopes from such blanks of the aforementioned machines.

SUMMARY OF THE INVENTION Accordingly it is a general object of the invention to overcome the disadvantages of the prior art.

' More particularly it is an object of the invention to provide an improved apparatus of the type here under discussion which is not possessed of these disadvantages.

Another object of the invention is to provide such an apparatus which is simple in its construction and has a high throughput per unit of time.

Still a further object of the invention is to provide such an apparatus which provides for the folding of envelope blanks to envelope configurations without the formation of folds or crinkles in the blank material, and consequently without the waste mentioned above.

In pursuance of these objects, and others which will become apparent hereafter, one feature of the invention resides in an apparatus for folding of envelope blanks requiring a plurality of folding operations, which apparatus briefly stated comprises a plurality of folding stations corresponding in number to the plurality of folding operations to be performed, and including one initial station and a terminal station. A plurality of rotary folding grippers and folding blades are provided on each of the folding stations, and drive means is provided for rotating the grippers and blades of the initial folding station so as to effect folding of a blank in one direction, and the grippers and blades of all other folding stations so as to effect folding of the blank in an opposite direction to the one direction. Removing means removes folded blanks from the terminal folding statlon.

The apparatus according to the present invention avoids the disadvantages of the prior art and provides the desired advantages. In particular it is an essential advantage of the novel apparatus that the production of the envelopes is now effected exclusively with rotary tools, that is rotary grippers and blades, which permit reliably the folding of the blank without forming crinkles in the blank material. In addition, the rotary tools can operate with a very high production speed, and they permit the apparatus to be constructed in a relatively simple manner.

Furthermore, the fact that the first folding station effects folding in a direction opposite to the direction of operation of the other folding stations, assures that in the finished folded blank the second closure flap which is located beneath the actual main closure flap is reliably located in the aforementioned position which has been described and which is required.

A particularly simple and therefore currently preferred embodiment of the invention provides for two cooperating cylinders, of which each is alternately provided on its circumference with folding blades and folding grippers, and which together form two folding stations. One of these cylinders constitutes with a further cylinder which is provided with folding blades spaced about its periphery, a third succeeding folding station.

An additional advantageous embodiment of the invention provides for the utilization of two cooperating cylinders of which each is provided alternating on its periphery with folding blades and folding grippers. These cylinders constitute with one another two folding stations. A second set of two cooperating cylinders constituting a further folding station is provided, and of these one is provided with folding blades and the other with folding grippers. Intermediate these two sets or pairs of cylinders is located a transporting cylinder provided with gripping devices and transporting the blanks to be folded between the pairs of cylinders. This arrangement is particularly advantageous if the envelopes to be folded are of large dimensions because if it were attempted to fold blanks for such envelopes of the previously mentioned embodiment in which one cylinder cooperates with two additional cylinders, the one cylinder might have to have such a large diameter that a full utilization of the apparatus capacity might be endangered.

The cylinders constituting the first and second folding station may be arranged to cooperate with advancing pressing bands which press the blanks against a cyl' inder periphery and which, advantageously, have a higher annular speed or velocity than the respectively cooperating cylinder.

It is also advantageous to provide a depositing device constituting part of the removing means and engaging and turning the blanks so that they can be deposited on a supporting table standing on edge. The supporting table is advantageously located between the turning device and the folding stations and the finished envelope blanks are thus deposited on the one hand in such a manner that they can be readily engaged in form of stacks and be removed, and on the other hand the positioning of the envelope blanks in this manner assures that the two closure flaps are constantly pressed by the turning device against the stack being formed so that an intercalation of the flaps of the envelopes during the deposition is avoided. The arrangement of the supporting table between the folding stations and the turning device also reduces the length of the machine and therefore the space requirements thereof.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a blank to be folded in the apparatus according to the present invention;

FIG. 2 shows the blank of FIG. 1 after it has undergone the first two folding operations, again in top-plan view;

FIG. 3 shows the blank of FIG. 1 in top-plan view after its conversion into an envelope;

FIG. 4 is a diagrammatic side-elevational view of an apparatus embodying the invention; and

FIG. 5 is a view similar to FIG. 4 but illustrating another apparatus embodying the invention in a somewhat different form.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing firstly the operations to be performed on a blank, in order to convert it from its planar state to a folded envelope, it will be seen that in FIGS. 1-3 I have illustrated the sequence of such folding operations. FIG. 1 shows the blank in planar condition, being identified with reference numeral 1 and having on its two longitudinal edges the already folded-over adhesive portions 2 and 3. At the two transversely extending edges there are provided strip-shaped adhesive coatings 4 and 5. The coating 4 is located at the underside and the coating 5 at the upper side of the blank, as seen in the top-plan view of FIG. 1.

Each of the folds 2 and 3 is provided with an adhesive coating 6 and 7, respectively, and the folding lines along which the blank is to be folded by the machine according to the present invention, are shown in broken lines and identified with reference characters I, II, and III, respectively. The sequence of folding of the blank 1 into the finished envelope of FIG. 3 is to be clearly determined from a comparison of FIG. 2 with FIG. 1, and from a comparison of FIG. 3 with FIG. 2.

The blank of FIGS. l-3 can be folded on an apparatus according to the present invention as illustrated in the embodiment of FIG. 4. In that embodiment the apparatus, which is diagrammatically illustrated and wherein non-essential components have been omitted for the sake of clarity, there is provided a cylinder 10 which cooperates with two additional cylinders 11 and 12, respectively. The arrangement is such in this embodiment that during one complete rotation of the cylinder 10, four envelopes are folded, and during one such complete rotation of the cylinder 10 each of the cylinders 11 and 12 performs two complete rotations.

It will be seen from FIG. 4 that equi-angularly distributed about the circumference or periphery of the cylinder 10 are four folding blades 13, l3, l3" and 13". These blades cooperate with folding grippers l4 and 14 of the cylinder 11 so that the blank is folded along the folding line I and the strip 8 located forwardly or upstream of the folding line I in the direction of advancement of the blank is folded to form the second lower closure flap, as shown in FIG. 2.

In addition to the folding blades 13' 13" the cylinder 10 is further provided, also equi-angularly distributed about its periphery, with folding grippers, l5, 15, 15', and 15". These cooperate with folding blades 16 and 16 provided on the cylinder 11 in such a manner that the blank 1 is folded along the folding line ll, so that the portion of the blank which is located forwardly of the folding line II as seen in the direction of advancement of the blank and which will constitute the back side of the finished envelope, is folded onto the front side of the blank. The cylinders 10 and 11 thus together constitute two first folding stations and a blank which has been processed by them will have the shape shown in FIG. 2.

A pressure member 16a presses the blank, or rather that portion thereof which is located forwardly of the folding line II as seen in the direction of advancement of the blank, against the associated cylinder. In order to assure that the portion 8 is also properly pressed and folded I provide advantageously advancing pressing belts 17 which are located at a slight spacing from the cylinder 10 and which advance at a rotary or angular speed which is greater than the angular speed of the cylinder 10.

Having passed the initial folding operation and having received the configuration shown in FIG. 2, the blank must be further folded to achieve the configuration shown in FIG. 3 wherein it has become an envelope. In order to do so there must be provided an additional subsequent folding station and for this purpose the cylinder 10 cooperates with folding blades 19 and 19' of the cylinder 12. To do so the cylinder 10 is provided with folding grippers 18, 18', 18" and 18 provided on its periphery and equi-angularly spaced thereabout. These grippers cooperate with the folding blades 19 and 19' in such a manner that the blank is folded along the fold line III and thus receives the configuration shown in FIG. 3, that is becomes converted into a finished envelope. In order to assure that the portion of the blank which is leading in direction of advancement of the blank, and is located forwardly of the fold line III, is properly folded over, the cylinder 12 is provided with suction devices 20 and 21 which engage the portion of the blank which is to be folded over, thereby facilitating the folding.

It is pointed out here parenthetically that no details such as the construction and operation of the folding blades, the folding grippers and the suction devices are given because this is entirely conventional and well known per se to those skilled in the art.

The folded envelopes are engaged and removed. For this purpose the device is provided with an upper turning roller or reversing roller 22a which is provided with gripping devices 22 and 23 which engage the finished envelope. Stripping members 24 are provided which serve to properly hand over the blanks from the cylinder to the roller 22a, and the thus handed-over blanks, or rather finished envelopes, are then engaged by a conveyor which is composed of an upper belt 25 and a lower belt 26, and which advances them to a depositing and reversing cylinder 27. The latter is provided with gripping devices 28, 28', 28", and 28", each of which can engage one of the finished envelopes and after turning it appropriately deposit it standing vertically on edge on a supporting table 29 which is located between the cylinder 27 and the folding stations. FIG. 4 also shows that the envelopes are so deposited that the two closure flaps formed during folding of the blank 1 into the envelope configuration are on the side facing away from the cylinder 27, so that an intercalation of adjacent envelopes is avoided during the deposition.

I have illustrated another exemplary embodiment of my novel apparatus in FIG. 5. Here again there are provided two cooperating cylinders 30 and 31 which together form the two first folding stations of the apparatus. Each of the cylinders 30 and 31 is provided alternately spaced about its circumference with respective folding blades and folding grippers. The cylinder 30 has the two folding grippers 32 and 32' and the two folding plates 33 and 33', and the cylinder 34 has four of the folding grippers, identified with reference numerals 34, 34', 34" and 34'. In addition the cylinder 31 has four of the folding blades, namely blades 35, 35, 35", and 35". By cooperation of the folding blades 3535" of the cylinder 31 and the folding grippers 32 and 32' of the cylinder 30 the blank 1 is initially again folded about the folding line I, whereas the folding of the blank about the folding line II is effected by cooperation of the folding blades 33, 33' of the cylinder 30 and the folding grippers 3434"'.

After the blank has passed through these two folding stations it will have the semi-finished configuration of FIG. 2. A pressure member 36 serves to press that portion of the blank which is located forwardly of the folding line 2 in the direction of advancement of the blank, against the respective roller, and the portion 8 is pressed against the respective roller by advancing pressing belts 37 which advance at a peripheral or angular speed greater than that of the cylinder 31.

When the blank has the semi-finished configuration of FIG. 2 it is engaged by a transporting and reversing cylinder 38 which is provided for this purpose with gripping devices 39,39, 39", and 39". Advancing belts 40 are convoluted about the cylinder 38 which engages the blanks and advances them to a further folding station composed of a cylinder 43 having folding blades 45 and 45 and a cylinder 42 having folding grippers 44, 44, 44" and 44". The belts 40 are partially trained also about the cylinder 42 and the latter is additionally provided with gripping devices 46, 46, 46" and 46" which receive the blank from the cylinder 38.

The blank is folded about the folding line III by the folding blades 45, 45' and the folding grippers 44, 44', 44" and 44", and thus assumes the configuration of the finished envelope as shown in FIG. 3. A pressure member 47 facilitates the folding operation by pressing the requisite blank portions which are to be folded onto one another. The finished envelope is then so deposited on the cylinder 42 that it contacts the same with the two closure flaps. Now the envelope advances from the cylinder 42 via the conveyor 25', 26 to the cylinder 27 which deposits them on the supporting table 29 in the manner discussed above with respect to the embodiment of FIG. 4.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in an apparatus for folding of envelope blanks, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by letters Patent is set forth in the appended 1. Apparatus for folding blanks, particularly envelope blanks, comprising a plurality of folding stations including an initial station and a terminal station, at least one of said folding stations comprising a rotatable member; a plurality of rotary folding grippers and folding blades provided on each of said folding stations with some of each of said grippers and blades being mounted on said rotatable member; drive means for rotating the grippers and blades of said initial station so as to effect folding of a blank in one direction, and for rotating the grippers and blades of all other folding stations so as to effect folding of the blank in an opposite direction to said one direction; and removing means for removing folded blanks from said terminal station.

2. Apparatus as defined in claim 1, wherein said blanks require a plurality of folding operations and the number of said folding stations is equal to the plurality of folding operations.

3. Apparatus for folding blanks, particularly envelope blanks, comprising a plurality of folding stations including an initial station and a terminal station, said folding stations comprising a first cylinder, a pair of second cylinders each cooperating with said first cylinder, and a third cylinder cooperating with one of the preceding cylinders; a plurality of rotary folding grippers and folding blades provided on each of said folding stations, each of said first and second cylinders being provided on its periphery with circumferentially spaced alternately arranged ones of said folding grippers and blades, and said third cylinder being provided on its circumference with a plurality of circumferentially spaced ones of said folding blades; drive means for rotating the grippers and blades of said initial station so as to effect folding of a blank in one direction, and for rotating the grippers and blades of all other folding stations so as to effect folding of the blank in an opposite direction to said one direction; and removing means for removing folded blanks from said terminal station.

4. Apparatus as defined in claim 3; further comprising at least one pressing belt for pressing an envelope blank against the periphery of said first cylinder.

5. Apparatus for folding of envelope blanks requiring a plurality of folding operations, comprising a plurality of folding stations corresponding in number to the plurality of folding operations and including an initial station and a terminal station, two of said folding stations .being constituted by a first pair of cooperating cylinders, and at least one additional one of said folding stations being constituted by a second pair of cooperating additional cylinders; a transport cylinder intermediate said pairs of cylinders for transporting an envelope blank from said first pair to said second pair; a plurality of folding grippers and folding blades provided on each of said folding stations, each of said first pair of cylinders being provided on its periphery with alternately arranged circumferentially spaced ones of said folding grippers and blades, and one of said second pair of cylinders being provided with circumferentially spaced ones of said folding grippers, the other of said second pair of cylinders being provided with circumferentially spaced ones of said folding blades; drive means for rotating the grippers and blades of said initial folding station so as to effect folding of a blank in one direction, and for rotating the grippers and blades of all other folding stations so as to effect folding of the blank in an opposite direction to said one direction; and removing means for removing folded blanks from said terminal folding station.

6. Apparatus as defined in claim 5, further comprising at least one pressing belt for pressing an envelope blank against the periphery of one of said cylinders of said first pair.

7. Apparatus as defined in claim 4, said first cylinder rotating at a first angular speed, and said pressing belt advancing relative to said first cylinder at a higher second angular speed.

8. Apparatus as defined in claim 6, said one cylinder of said first pair rotating at a first angular speed, and said pressing belt advancing relative to said one cylinder at a higher second angular speed. v

9. Apparatus as defined in claim 5, said one cylinder of said second pair comprising gripping devices in addition to said folding grippers.

10. Apparatus as defined in claim 1, said removing means comprising blank-depositing means for depositing the respective blanks on edge on a supporting surface.

11. Apparatus as defined in claim 10; further comprising a supporting table provided with said supporting surface and located between said folding stations and said blank-depositing means.

12. Apparatus as defined in claim 10, said blankdepositing means including a rotary cylinder element and a plurality of gripping devices provided on the same.

13. Apparatus as defined in claim 3; and further comprising suction devices provided on said third cylinder. 

1. Apparatus for folding blanks, particularly envelope blanks, comprising a plurality of folding stations including an initial station and a terminal station, at least one of said folding stations comprising a rotatable member; a plurality of rotary folding grippers and folding blades provided on each of said folding stations with some of each of said grippers and blades being mounted on said rotatable member; drive means for rotating the grippers and blades of said initial station so as to effect folding of a blank in one direction, and for rotating the grippers and blades of all other folding stations so as to effect folding of the blank in an opposite direction to said one direction; and removing means for removing folded blanks from said terminal station.
 2. Apparatus as defined in claim 1, wherein said blanks require a plurality of folding operations and the number of said folding stations is equal to the plurality of folding operations.
 3. Apparatus for folding blanks, particularly envelope blanks, comprising a plurality of folding stations including an initial station and a terminal station, said folding stations comprising a first cylinder, a pair of second cylinders each cooperating with said first cylinder, and a third cylinder cooperating with one of the preceding cylinders; a plurality of rotary folding grippers and folding blades provided on each of said folding stations, each of said first and second cylinders being provided on its periphery with circumferentially spaced alternately arranged ones of said folding grippers and blades, and said third cylinder being provided on its circumference with a plurality of circumferentially spaced ones of said folding blades; drive means for rotating the grippers and blades of said initial station so as to effect folding of a blank in one direction, and for rotating the grippers and blades of all other folding stations so as to effect folding of the blank in an opposite direction to said one direction; and removing means for removing folded blanks from said terminal station.
 4. Apparatus as defined in claim 3; further comprising at least one pressing belt for pressing an envelope blank against the periphery of said first cylinder.
 5. Apparatus for folding of envelope blanks requiring a plurality of folding operations, comprising a plurality of folding stations corresponding in number to the plurality of folding operations and including an initial station and a terminal station, two of said folding stations being constituted by a first pair of cooperating cylinders, and at least one additional one of said folding stations being constituted by a second pair of cooperating additional cylinders; a transport cylinder intermediate said pairs of cylinders for transporting an envelope blank from said first pair to said second pair; a plurality of folding grippers and folding blades provided on each of said folding stations, each of said first pair of cylinders being provided on its periphery with alternately arranged circumferentially spaced ones of said folding grippers and blades, and one of said second pair of cylinders being provided with circumferentially spaced ones of said folding grippers, the other of said second pair of cylinders being provided with circumferentially spaced ones of said folding blades; drive means for rotating the grippers and blades of said initial folding station so as to effect folding of a blank in one direction, and for rotating the grippers and blades of all other folding stations so as to effect folding of the blank in an opposite direction to said one direction; and removing means for removing folded blanks from said terminal folding station.
 6. Apparatus as defined in claim 5, further comprising at least one pressing belt for pressing an envelope blank against the periphery of one of said cylinders of said first pair.
 7. ApparaTus as defined in claim 4, said first cylinder rotating at a first angular speed, and said pressing belt advancing relative to said first cylinder at a higher second angular speed.
 8. Apparatus as defined in claim 6, said one cylinder of said first pair rotating at a first angular speed, and said pressing belt advancing relative to said one cylinder at a higher second angular speed.
 9. Apparatus as defined in claim 5, said one cylinder of said second pair comprising gripping devices in addition to said folding grippers.
 10. Apparatus as defined in claim 1, said removing means comprising blank-depositing means for depositing the respective blanks on edge on a supporting surface.
 11. Apparatus as defined in claim 10; further comprising a supporting table provided with said supporting surface and located between said folding stations and said blank-depositing means.
 12. Apparatus as defined in claim 10, said blank-depositing means including a rotary cylinder element and a plurality of gripping devices provided on the same.
 13. Apparatus as defined in claim 3; and further comprising suction devices provided on said third cylinder. 